Improved gtk-close icon for dark themes

[Milan Bouchet-Valat]

The gtk-close.png icon at 12x12 size is not really nice when used in menus under dark themes: the four pixel at the corners look white, which is strange. You can see this in the File menu of the GIMP, using for example the Dust theme. As those are getting more popular (and Dust uses Human for its icons), it may be good to support them.

I changed quickly these four pixels to use the orange from the rest of the icon, so that the icon is really a square, which is not rally visible at this size, but removes the white points. Anyway, have a look at that little change. If you have a better way of fixing this, please just throw away this one.

[Kenneth Wimer (kwwii)]

Excellent, thanks for the good work. I will see to it that this is included in the next update of the human theme

[Milan Bouchet-Valat (nalimilan)]

Glad to know you like this kind of contribution. This is not really "good work", only a little tweak, but I'll try provide other fixes like that (I believe the 22x22 size is missing for this icon).